1. Field of the Invention
The present invention relates to a circuit device, and particularly to a circuit device in which thermal interference between elements is suppressed.
2. Description of the Related Art
With reference to FIG. 5, a description will be given of a configuration of a hybrid integrated circuit device 100 as an example of a conventional circuit device. Firstly, a conductive pattern 103 is formed on a surface of a rectangular substrate 101 with an insulating layer 102 interposed therebetween. Circuit elements are fixed to desired portions of the conductive pattern 103, and thereby a predetermined electrical circuit is formed. Herein, a semiconductor element 105A and a chip element 105B are employed as the circuit elements. The semiconductor element 105A is, for example, a transistor or a diode. An upper-surface electrode of the semiconductor element 105A is connected to a predetermined part of the conductive pattern 103 through a metal wire 107. A back-surface electrode of the semiconductor element 105A is connected to a conductive pattern 103A. Meanwhile, the chip element 105B, which is a capacitor or a resistor, has, in its both ends, electrodes connected to the conductive pattern 103 through a bonding material 106 such as a solder. In addition, a sealing resin 108 has a function to seal the electrical circuit formed on the surface of the substrate 101.
On an upper surface of a hybrid integrated circuit with the above configuration, a circuit for switching a high current such as an inverter circuit is constructed, for example (see, Japanese Patent Application Publication No. 2007-036014).
However, when multiple power transistors are arranged in a small region for the purpose of miniaturization of the entire device incorporating, for example, an inverter circuit, these transistors thermally interfere with each other, and thereby cause a problem that the junction temperature thereof becomes higher than the temperature caused by self-heating.
In contrast, when transistors are arranged to be spaced apart from each other in order to avoid the above problem, another problem arises that miniaturization of the device in total size cannot be achieved even though thermal interference is suppressed.
The present invention has been made in view of these problems, and a main object of the present invention is to provide a circuit device having a configuration in which thermal interference between built-in elements is suppressed, and being miniaturized in total size.